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Thread: Limiters holding me back to only 1600 RPM?

  1. #1
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    Question Limiters holding me back to only 1600 RPM?

    I'm guessing that's what it is?

    Anytime I've been trying to make adjustments to my injection pulses table, I'm unable to go past 1600 and it just limps around..
    I did some quick changes to simply see if I could get it to go away quickly, but still didn't have any luck?
    This is what I did to see -

    Changed my Maximum Fuel Quantity Before Reduction 1 by increasing it by 20% across
    I left the Maximum Fuel Quantity Before Reduction 2 at 150
    Then I took the Maximum Fuel Quantity Final to 150 across


    Is there something I'm missing regarding the fueling limiters? I would have figured this would have resolved the problem?

    Sorry I'm a bit new to EFILive and come from tuning a lot of gas cars.

  2. #2
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    Or is there some write up somewhere about them specifically for the LML application? I can't seem to find anything.. The LML doesn't have as much of a support group/community as the older ones it looks like.

  3. #3
    Lifetime Member GMC-2002-Dmax's Avatar
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    Unfortunately you will not get much help on LML, its going to be a steep curve especially coming from the gas world.

    Keep playing around with it, eventually you will get some progress.

    Good Luck
    www.mscservices.net


    Tuner of many, many Duramax and Cummins Diesels.


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    Yeah, I'm sure I'll figure it out with time. I was just hoping someone here could enlighten me a bit quicker. It seems like the EFI community doesn't like sharing much info for the most part I've seen which is too bad :/

  5. #5
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    Well for starters, changing the fuel limiters doesn't really do a whole lot.

    When you increase the pulse duration, you effectively increase the mm3 injected, but it won't register to the ECM because you are pretty much lying to the ECM.

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    Quote Originally Posted by Snipesy View Post
    Well for starters, changing the fuel limiters doesn't really do a whole lot.

    When you increase the pulse duration, you effectively increase the mm3 injected, but it won't register to the ECM because you are pretty much lying to the ECM.
    I guess I'm failing to understand then. Isn't the "Injection Pulses" table the global fueling table? I figured if I would have changed that to accommodate any fuel needs, I would just respectively adjust the Max Fuel Quantity tables along with it and possibly the "Torque to fuel" table to allow however many microseconds I have increased at whatever mm3 and mpa orientation?

    Can someone please enlighten me a bit more on this? Hell, I'd be willing to even pay for a crash course if someone would give me the time of day too.

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    Quote Originally Posted by Import_Dude View Post
    I guess I'm failing to understand then. Isn't the "Injection Pulses" table the global fueling table? I figured if I would have changed that to accommodate any fuel needs, I would just respectively adjust the Max Fuel Quantity tables along with it and possibly the "Torque to fuel" table to allow however many microseconds I have increased at whatever mm3 and mpa orientation?

    Can someone please enlighten me a bit more on this? Hell, I'd be willing to even pay for a crash course if someone would give me the time of day too.
    The pulse table is used for everything, even the pilot and post injections. So yes it is the global fueling table. The ECM says hey, I want to inject x mm3 of fuel. It then looks at the table to see how long that injection is, and then turns on the injector for that long, regardless of how much mm3 actually gets injected.

    But it does cause alot of problems. The ECM and TCM are pretty good at knowing something is wrong. 400 NM of torque is commanded, 500nm gets delivered. They see that, and will adjust to try and fix the issue.

  8. #8
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    Quote Originally Posted by Snipesy View Post
    The pulse table is used for everything, even the pilot and post injections. So yes it is the global fueling table. The ECM says hey, I want to inject x mm3 of fuel. It then looks at the table to see how long that injection is, and then turns on the injector for that long, regardless of how much mm3 actually gets injected.

    But it does cause alot of problems. The ECM and TCM are pretty good at knowing something is wrong. 400 NM of torque is commanded, 500nm gets delivered. They see that, and will adjust to try and fix the issue.
    So it sounds like you're saying it may just be my TQ to Fuel tables then? I'll try increasing them a bit more with everything else to see if it eliminates the problem. Also, out of curiosity, would would happen if there was more MM3 at a given NM than everything else added up for the injection? Would it try to add more in to reach the targeted MM3 at the given TQ value? Or is that table just strictly defined more so of a maximum MM3 value - If exceeded, cut TPS.

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